Referring to the Critical vulnerability in Apache Log4j library, about which you can read in the link below will show a simple script with which we will be able to diagnose whether there is log4j on our system.

How check this ?

  • Download script and run
##For Ubuntu
root@master:/home/ozyrys# wget
root@master:/home/ozyrys# chmod +x
root@master:/home/ozyrys# ./
##For CentOS
root@master:/home/ozyrys# wget
root@master:/home/ozyrys# chmod +x
root@master:/home/ozyrys# ./

Photo by Glenn Carstens-Peters on Unsplash

Command Comparison

Since TSV import is troublesome for both MySQL and PostgreSQL, it is best to create your own script to convert TSV to SQL.

PostgreSQL/MySQL information_schema

Since information_schema is a SQL standard, the same SQL can be used in either case.

Table list

Column list

Setup Default Connection

In PostgreSQL this is set by environment variable

export PGDATABASE = DB name
export PGHOST = host
export PGPORT = port number
export PGUSER = username
export PGPASSWORD = password

The password can also be set with ~/.pgpass

In MySQL we can set all in ~/.my.cnf

database = DB name
user = username
password = password


If you really forget all the options, just type journalctlto see all the saved logs, if a long line is truncated, you can scroll to the right by pressing the arrow keys

Let’s start

View recent messages

root@test:/home/ozyrys# journalctl -e

Detailed information

root@test:/home/ozyrys# journalctl -ex

Monitor logs just like tail -f

root@test:/home/ozyrys# journalctl -f

Show only messages for specific services

root@test:/home/ozyrys# journalctl -u sshd

You can specify the full path of the executable file as in.

root@test:/home/ozyrys# journalctl /usr/sbin/sshd

Display only the end of the log

root@test:/home/ozyrys# journalctl -n 100

Display all messages from startup

root@test:/home/ozyrys# journalctl -b

Photo by Panos Sakalakis on Unsplash


I will show you how to quickly change the proxy of the browser and the LAN to connect to using the command line.

You need administrator privileges to execute the command .


Check Interface Name

netsh interface show interface

Virtual settings


  • Proxy:
  • Ip Address:
  • Mask:
  • Gateway:
  • DNS:


  • Proxy:
  • Ip Address:
  • Mask:
  • Gateway:
  • DNS:

Switch to Settings01

Switch to Settings02



DevOps Consultant. I’m strongly focused on automation, security, and reliability.